<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    <style>
        .item{
            border:1px solid red;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="row">
            <div class="item col-sm-4">123</div>
            <div class="item col-sm-4">123</div>
            <div class="item col-sm-4">123</div>
        </div>
    </div>
</body>
</html>